There presently exists a wide variety of filter screens and mounting therefore. Some are single screens made of a single type media however others provide a double filter unit. In such double screen units there is usually involved a fine screen media with a backup or coarse media spaced therefrom in tandem. Both filters are usually fixedly attached to a support means, such as a metal hoop or frame during assembly. This prefabrication is therefor required prior to shipping to the consumer. The filter unit is then usually placed into a support provided in a filter tank.
It has been found that while such an arrangement may be satisfactory in certain circumstances, it suffers certain disadvantages. Firstly, transportation of such filter units for replacement or repair, etc., is bulky and expensive. Also, should a different type fine or coarse filter in the combination be desirable replacement of the entire filter unit is required rather than a mere substitution. This applies equally to the repair or replacement of a damaged filter which would require a return of the entire unit for working, or its entire replacement. Accordingly, with prior filter units, the user of such filters had limited flexibility regarding filter selection and replacement of individual filter screens.